Tail gate operating mechanism for dump trucks



Sept. 3, 1940. T. J. DAILEY I TAIL GATE OPERATING MECHANISM FOR DUMP TRUCKS Filed D60. 27, 1938 $NVENTOR A13RNE3 a 5 Patented Sept. 3, 19 40 2 2 E 3 3 5,

UNITEo smresraraur c erics TAIL GATE OPERATING MECHANISM FOR DUNE TRUCKS Timothy J. Bailey, Rochester, N. Y. Application December 27, 1938, Serial No. 247,868 4 Claims. (01. 298-23) This invention relates to a tail gate operating applied can be of any usual and well known conmechanism for dump trucks and more particustruction, the dump truck illustrated in the aclarly to such a mechanism which operates autocompanying drawing being of a conventional matically to swing the tail gate to open and type. and having longitudinal chassis bars l 5 closed positions as the body is raised and lowered s ppo ted y Whee s H nd Carrying the usual thereby to facilitate the discharge of materials dump body l2 and cab l3. The dump body l2 from the dump truck and the restoring of the is shown as being pivoted to the chassis bars I!) dump truck to its normal condition for again at i l so that the body can be swu from the being filled. horizontal position illustrated in Fig. 1 to the [0 One of the objects of the invention is to proincli ed position i ust a ed n Fi the matevide a simple and positive mechanism for autorials within the dump body sliding out the rear matically opening the tail gate when the dump pe nd of t e body w e it s v ed to the truck body is raised for the purpose of dischargposition shown in Fig. 2. Any usual and well ing the materials therefrom and for autoknown mechanism can be employed for l t n 16' matically restoring the tail gate to a closed posithe dump body 92 and restoring it to a hori ontal tion as the body is lowered. position, that shown comprising a cylinder l5 Another object of the invention is to provide carried by the chassis and housing a piston (not such a mechanism in which the tail gate is at shown) of a piston rod it which piston rod is in alltimes held close to the dump truck body so turn connected with the dump body. Upon the 20 that there is no interference with surrounding admission of a fluid under pressure into the 20 structure and the materials can be discharged ylind r i he pi n i riv n w d y, h at any place desired. by to lift the dump body to the position shown in Another purpose of the invention is to provide Fig. 2. Upon release of this fluid pressure the such an automatic tail gate operating mechadump body returns by gravity to its horizontal nism in which the tail gate is automatically position, the cylinder and piston rod swinging 25 latched in its closed position by the dropping into a nested position under the body as it reof the dump truck body, thereby to avoid the turns to such horizontal position.

necessity of a special latching mechanism toin- The tail gate 20 can be of any suitable consure against loss of goods in transit. struction and is shown as composed of a sheet Another object of the invention is to provide metal plate 2! reenforced at its sides by vertical 30.

such a mechanism in which the opened tail gate angle irons 22. The tail gate is hung upon a swings freely so that there is no danger of horizontal rod 23 which passes through the upbreaking any parts during the discharge of per ends of the angle irons 22, as best shown in materials. Fig. 3. Each end of the rod 23 is in turn supsuch an automatic operating mechanism which 2d being pivoted to the corresponding side of is extremely low in cost and rugged in constructhe dump truck body l2, as indicated at 25. The tion and at the same time nests in such a manopening and closing of the tail gate is effected nor as not to interfere with any other parts of by moving the arms 2t upwardly and downthe truck. wardly as the dump truck is raised and lowered. 40

In the accompanying drawing: When the body is brought to a horizontal posi Fig. 1 is a fragmentary side elevation of a dump tion and the arms 24 lowered, the lower end of truck equipped with a tail gate operating mechathe tail gate can be caught by any suitable form nism made in accordance with my invention. of latching device. The latching device illus- 5 Fig. 2 is a fragmentary view similar to Fig. 1 trated is shown as comprising one or more showing the dump truck body in its elevated or brackets 25 secured to the rear end of the dump dumping position and the tail gate automatically body l2 and having an upturned portion 2'! opened by the mechanism forming the subject which catches the lower end of the tail gate as of my invention. it descends.

Fig. 3 is a fragmentary top elevation of a dump The tail gate is mounted on the rod 23 for 50 truck body showing parts broken away to illusfree swinging movement and hence assumes a trate the tail gate operating mechanism. vertical position as it is raised and lowered. It

Fig. 4 is a fragmentary vertical transverse secwill therefore be seen that as the tail gate and tion taken on line 4-4, Fig. 1. dump body are lowered, the lower edge of the The dump truck. to which my invention can be tail gate will automatically be caught by the 55 25' Another object of the invention is to provide ported at the rear end of an arm 24, each arm 35 brackets 26 and it will further be seen that the start and discharge of materials from the dump body will occur as soon as the tail gate is lifted free from the brackets 26, since the pressure of the materials within the body will swing the tail gate rearwardly as soon as this release occurs. It will also be noted that since the tail gate assumes a vertical position it is constrained to follow a path which hugs the rear end of the dump body so as to avoid possible interference with surrounding structure.

The mechanism for automatically raising the arms 2d as the dump body I2 is raised is shown as comprising a pair of rock arms 30 which are keyed to a rock shaft 3!, this rock shaft being arranged under the dump body I2 and being journaled to the dump body in any suitable manner. The outer end of each of the rock arms 30 is connected by a link 32 with the central part of the corresponding arm 24. The rock shaft 3| is operated by a rock arm 33 which extends forwardly from the rock shaft 3! and is secured thereto in any suitable manner. The free or for- Ward end of the operating rock lever 33 is connected to the adjacent chassis frame bar In by a link 3d, the pivotal connection between this link and chassis frame bar being indicated at 35.

It will be seen that as the dump body I2 is raised, the rock shaft Si is moved away from the pivot 35 and hence the rock arm 33 is swung downwardly away from the dump body as it rises. This effects a corresponding movement of the rock shaft 3| which in turn swings the pair of rock arms 3!] upwardly. This upward movement of the rock arms 30 raises the links 32 which in turn raise the arms 24 so as to swing the tail gate 20 from the latched position shown in Fig. 1 to the open position shown in Fig. 2. After the materials have been dumped from the dump body l2 the lowering of the dump body effects a reverse movement of the rock levers and links so that the tail gate is returned to the position shown in Fig. 1 and is automatically caught by the brackets 26.

From the foregoing it will be seen that the present invention provides a very simple and rugged mechanism for automatically swinging the tail gate of a dump truck to open and closed positions as the dump body is raised and lowered. It will also be seen that the tail gate is automatically latched when it assumes its closed position and is also constrained to move in such manner as not to interfere with surrounding structure. The system of levers and links shown also nest compactly when the dump body assumes its normal horizontal position and do not interfere with any of the other operating parts of the truck.

I claim as my invention:

1. The combination with a dump truck having a chassis, a dump body mounted thereon and means for raising said dump body about a fixed horizontal axis to discharge the contents thereof, of a tail gate at the discharge end of said body, a carrying member pivotally mounted at its front end on said body adjacent the rear end thereof, means pivotally connecting said tail gate to the rear end of said carrying member and permitting said tail gate to swing about a horizontal axis, and means interconnecting said carrying member, dump body and chassis for opening said tail through motion derived from the discharging movement of said dump body and for closing said tail gate through motion derived from the return movement of said dump body comprising a rock shaft mounted on said dump body, a rock lever fixed at one end thereof to said rock shaft, a link interconnecting the free end of said rock lever with said carrying member at a point intermediate the ends thereof, a second rock lever fixed to said rock shaft and a second link interconnecting said second rock lever with said chassis.

2. The combination with a dump truck having a chassis, a dump body mounted thereon and means for moving said dump body on a horizontal axis to discharge the contents thereof, of a tail gate at the discharge end of said body, a pair of arms pivotally secured to opposite sides of said dump body near the rear end thereof, means pivotally supporting the tail gate on the rear ends of said arms whereby said tail gate is free to swing around a horizontal axis, a rock shaft journaled on said body at the bottom thereof, a pair of rock arms fixed to said rock shaft and extending rearwardiy therefrom, a link connecting the rear end of each of said rock arms with an intermediate portion of the corresponding tail gate carrying arm, a third rock arm fast to said rock shaft and extending forwardly therefrom and a link connecting the free forward end of said last rock arm with an adjacent part of said chassis.

3. The combination with a dump truck having a chassis, a dump body mounted thereon and means for raising said dump body about a fixed horizontal axis to discharge the contents thereof, of a tail gate at the discharge end of said body, a carrying member pivotally mounted at its front end on said body adjacent the rear end thereof, means pivotally connecting said tail gate to the rear end of said carrying member and permitting said tail gate to swing about a horizontal axis, means interconnecting said carrying member, dump body and chassis for opening said tail gate through motion derived from the discharging movement of said dump body and for closing said tail gate through motion derived from the return movement of said dump body comprising a rock shaft mounted on said dump body, a rock lever fixed at one end thereof to said rock shaft, a link interconnecting the free end of said rock lever with said carrying member at a point intermediate the ends thereof, a second. rock lever fixed to said rock shaft and a second link interconnecting said second rock lever with said chassis, and means for latching said tail gate to said body during the last part of the closing movement of said tail gate.

4. The combination with adump truck having a chassis, a dump body mounted thereon and means for moving said dump body on a horizontal axis to discharge the contents thereof, of a tail gate at the discharge end of said body, a pair of arms pivotally secured to opposite sides of said dump body near the rear end thereof, means pivotally supporting the tail gate on the rear ends of said v hereby said tail gate is free to swing around a horizontal axis, a rock shaft iournaled on said body at the bottom thereof, a pair of rock arms fixed to said rock shaft and extending rearwardly therefrom, a link connecting the rear end of each of said rock arms with an intermediate portion of the corresponding tail gate carrying arm, a third rock arm fast to said rock shaft and extending forwardly therefrom, a link connecting the free forward end of said last rock arm with an adjacent part of said chassis, and means for latching said tail gate to said body during the last part of the closing movement of said tail gate. 

